1231355 has 4 divisors (see below), whose sum is σ = 1477632. Its totient is φ = 985080.

The previous prime is 1231339. The next prime is 1231357. The reversal of 1231355 is 5531321.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 1231355 - 2⁴ = 1231339 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1231357) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 123131 + ... + 123140.

It is an arithmetic number, because the mean of its divisors is an integer number (369408).

2^1231355 is an apocalyptic number.

1231355 is a deficient number, since it is larger than the sum of its proper divisors (246277).

1231355 is an equidigital number, since it uses as much as digits as its factorization.

1231355 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 246276.

The product of its digits is 450, while the sum is 20.

The square root of 1231355 is about 1109.6643636704. The cubic root of 1231355 is about 107.1834567829.

Adding to 1231355 its reverse (5531321), we get a palindrome (6762676).

The spelling of 1231355 in words is "one million, two hundred thirty-one thousand, three hundred fifty-five".